The statements in this section merely provide background information related to the present disclosure and may or may not constitute prior art.
In most manual, semi-automatic and automatic motor vehicle transmissions, forward speed ratios (gears) are achieved by selectively engaged pairs of gears or planetary gear sets. Reverse gear is generally achieved by incorporating an additional, direction reversing idler gear between a pair of gears, causing the transmission output to rotate on the opposite direction relative to all the other selected gears or gear ratios.
This reverse idler, although standard transmission design practice, is not without its drawbacks. First of all, it necessitates at least one component on an additional axis, offset form the axis or axes of the transmission shafts. Although the reverse idler gear on the additional axis is generally not large, it may still present transmission and driveline packaging issues. Clearly, the transmission housing must be configured to not only accept the reverse gear idler but also accommodate a supporting shaft. Second of all, the reverse idler gear, of course, requires the shaft with suitable bearings, all components that add weight and cost to the transmission. Last of all, the conventional reverse idler gear train can be noisy and creates significant parasitic losses due to the multiple gear meshes. It is apparent that improvements in transmission reverse gear configurations are therefore desirable.